Traditional acoustic black hole (ABH) changes the impedance by power law cutting of the material to achieve elastic wave focusing or control. But, at the same time, the material structure is destroyed, the rigidity of the material is reduced, and its application is limited in the field of elastic wave detection as a sensibilization structure. In this article, an upside-down adhesive ABH structure is proposed. In a certain range, its thickness change conforms to the power attenuation law, and it is small and easy to attach to the surface of the object to be measured without damaging the object. Finite element simulation results show that the inverted ABH has about 7 times of elastic wave amplification effect near the center of the circle under medium and high frequency excitation. Scanning test with the laser Doppler vibrometer shows that the inverted ABH has good elastic wave focusing effect and can amplify the elastic wave about 2-4 times. fiber Bragg grating(FBG) is bonded on the surface of the inverted ABH and the intensity demodulation is utilized to form an elastic wave sensor with focusing and amplification effect, which has important application value in the domain of nondestructive testing.